Micro-adjustable strip stock feeder



Feb. 5, 1963 A. F. GROLL 3,076,363

MICRO-ADJUSTABLE STRIP STOCK FEEDER Filed April 10, 1959 s Sheets-Sheet 1 ALVIN F. GROLL ATTORN YS Feb. 5, 1963 A. GROLL 7 3,

MICRO-ADJUSTABLE STRIP STOCK FEEDER Filed April 10, 1959 3 Sheets-Sheet 2 INVENTOR.

ALVIN F. GROLL BY ATTORN YS A. F. GROLL MICRO-ADJUSTABLE STRIP STOCK Feb. 5, 1963 3 Sheets-Sheet 3 Filed April 10, 1959 ATTOR EbYS crank and connecting link.

United States Patent 3,076,368 MICRO-ADJUSTABLE STRIP STOCK FEEDER Alvin F. Groll, Box 347, Napoleon, Ohio Filed Apr. 10, 1959, Ser. No. 805,502 2 Claims. (Cl. 83244) This invention relates to mechanisms for feeding sheet metal strip stock into devices which consume precise quantities of the stock in step-by-step fashion as exemplified by power presses which punch and form shapes from such strip stock. The purpose of such feeders is to withdraw uniform and accurately adjusted lengths of strip stock from coils of sheet metal strip stock and to feed the strip stock so withdrawn to the mechanism utilizing it.

Feeders are of many specific types but most of them have jaws or rollers between which strip stock is intermittently clamped or pinched and advanced through predetermined incrementsof movement. After each ad vance the strip stock usually remains stationary in the machine processing it while it is processed. In a press it is held stationary above a die block while a shape is being punched out of the strip by means of a ram.

The ram of the stock utilizing device may be operated hydraulically or it may be reciprocated by means of a In installations of the type reciprocatory motion.

in which a feeder is incorporated with a power press or shear the ram of which is operated by a crank and connecting link, the feeder usually is operated by a supplemental crank on the same crank shaft that carries the crank operating the ram, the angular relation between the cranks being such that the strip stock is advanced while the ram is in the upper part of'its stroke.

It is important that each increment of advance of the strip stock be of such length as to present a sufficient area of stock between the stock working elements such as the punch and die of the press to provide for a complete shape; but any excess in the length of stock thus presented becomes waste, which increases the cost of producing the shapes. The length of the increment of advance usually is adjusted to be somewhat more than suflicient, in order to guard against the production of imperfect shapes resulting from slippage, variations in thickness of stock or for other reasons the increments of movement temporarily run short. In most prior art devices the lengths of the increments of advance of the strip stock can be adjusted by stopping the machine and changing the throw of the auxiliary crank, or making some other dimensional change, then starting the machine and making a test run to determine whether or not the change that has been made was too great or too small.

The principal object of thisinvention is to provide a strip stock utilizing device having a reciprocating element and having incorporated therewith a micro-adjustable strip stock feeder in which the lengths of increments of advance of; the strip can be micro-adjusted while i the utilization device and feeder are operating.

Another object of the invention is to provide a strip stock utilization device and strip stock feeder combination having a handle mounted on a stationary part of the machine frame, which handle, while the machine is running, can be conveniently manipulated to effect microadjustments of increments of advance of strip stock.

Other objects and numerous advantages of the inven- 3,076,368 Patented Feb. 5, 1963 stock feeder combination incorporating one form of micro-adjusting means of this invention;

FIG. II is a front elevational view showing part of the same form of power press and strip stock feeder combination incorporating th same form of micro-adjusting means of this invention;

FIG. III is a fragmentary front sectional view on an enlarged scale showing details of adjusting mechanism; and

FIG. IV is a fragmentary sectional view on a less enlarged scale taken substantially as indicated by the line IVIV of FIG. III.

This description and the accompanying drawings are to describe and illustrate a preferred form of the invention but are not to impose limitations upon the scope of the invention.

The form of the invention described and illustrated by the accompanying drawings is incorporated in a power press and strip stock feeder combination of the type described and illustrated in United States Patent No. 2,728,571 issued to this inventor December 27, 1955. The power press in this form of machine is constructed with a frame 1 in which a ram 2 is mounted for vertical The lower end of the ram 2 is fitted with a chuck 3 in which various shapes of punches or other tools may be mounted. A bolster 4 is securely mounted on the frame beneath the ram 2 and die blocks 5 of various shapes may be mounted on the bolster'4 for cooperation with punches mounted in the chuck 3.

The ram 2 is reciprocated by a crank shaft 6, crank.7 and connecting link 8. The crank shaft may be driven by an electric motor or other source of power through suitable gearing which also is commercially available. Neither the source of power nor the gearing is shown in the drawings or described herein.

In the form of device shown, the complete feeder may comprise two substantially identical feeder units 9 that are mounted on each side of the die block 5 to push and pull the strip stock through the press, or it may consist of a single unit which pushes the strip stock through. Each feeder unit 9 includes a sturdy generally U-shaped frame 10 which supports a feed roll 12 and a pressure roll 13. The feed roll 12 is mounted on a heavy shaft 14, that is journaled in the frame 10, with the upper surface of the feed roll 12 at substantially the same level as the face of the die that is held by the die block 5. The feed roll shaft 14 is connected through suitable gearing and an overrunning clutch (not shown) to a pinion 18 which meshes with a rack 19, so that as the rack 19 moves up and down the feed roll 12 is rotated intermittently through the overrunning clutch cooperating with an intermittently acting brake (not shown) to feed the strip stock in separate increments.

. The machine as so far described is disclosed in my United States Patent No. 2,728,571. The known mechanism of that prior patent is described herein only in 'new features therewith to be Well understood.

tion will become apparent upon perusal of the follow-' I ing specification illustrated by the accompanying drawings, in which:

FIG. I is a side elevational view of a part of one form of a power press typical of the strip stock utilizing devices with which this invention is concerned and strip The rack 19 is fixed to the lower end of a rack bar 20 the upper end of which is pivoted upon the nose pivot 21 of a lever 22 which is pivoted upon a fulcrum pivot 23 that is fixed to a bracket24 of special construction secured by means of rivets 25 or similar fasteners to th frame 1 of the power press.

Fixedly mounted upon an end of the power press crank shaft 6 is a fitting 26 that is provided with an end face 27 having a radially extending slot 28 within whichthe head of a crank pin 29 may be clamped at a selecteddistance from the turning axis of the crank shaft 6. The upper end of a connecting link 30 is journaled upon the crank aovaees pin 2? while the lower end of the connecting link 30 is pivotally connected to the lever 22 at the levers power pivot 31, which is located between the levers nose pivot 21 and its fulcrum pivot 23. For the sake of simplicity, the elements 22 to 31 inclusive are shown schematically in FIGS. I and II.

The fitting 26 with its slotted end face 27 and the crank pin 29 constitute an auxiliary crank the throw of which can be preliminarily adjusted to predetermine the angular movement of the lever 22, the endwise movement of the rack 19, the turning movement of the pinion 18 and the feed and pressure rolls 12 and 13, and the consequent lengths of the increments of advance of the' sheet metal strip stock that is being fed through the power press.

Adjustment of the increments of advance of the sheet metal strip stock must be made empirically when the lengths of the increments are adjusted by varying the throw of the auxiliary crank pin 29. If, for instance, the increments of advance are observed to be too great the press must be stopped and the crank pin 29 moved radially inwardly along the slot 28 and clamped in its new position. The press then must be restarted and run for sufficient time to enable the attendant to determine whether or not the new lengths of the increments of advance of the strip stock are proper.

The procedure of adjustment by trial and error may take the power press and its adjuncts out of production frequently, and it often keeps them out of production for considerable periods. It is quite difiicult even for a skilled attendant to accomplish an exact adjustment of increments of advance of strip stock by stopping the press and adjusting the throw of the crank while the mechanism is not running. Proper location of the crank pin 29 in the slot 28 is useful, however, for preliminary adjustment in the device of this invention fine adjustment of the lengths of increments of advance of the strip stock is achieved by changing the lengths of the power arm and work arm of the lever 22 and the ratio of the lever arms to each other, as well as the angles at which the connecting link 30 and the rack bar 29 extend from the lever 22. The construction of the micro-adjusting mechanism is such that it can be manipulated while the machine is running, thus avoiding loss of time and spoilage of product incident to stopping the mechanism and adjusting it while it is not running.

As may be observed by inspection of FIG. IV, the fulcrum pin 23 is divided into two aligned parts which are fixed to the bracket 24 and extend into bearings 32 in a slide 33 which is mounted for endwise adjustment in the hollow end 34 of the lever 22. The slide 33 is prevented from rotating in the hollow end 34 of the lever 22 with respect to the lever axis by a key 35 or equivalent means. The slide 33 has a bore 36 extending endwise therethrough which bore is enlarged at its ends by counterbores 37 and 38. Rotatably fitting within the bore 36 is the specially shaped head 39 of a screw 40 which is threaded into a solid portion 41 of the lever 22. The shaped head 39 of the screw 40 is surrounded by an integral collar 42 which fits into the counterbore 37 and is held therein by a retaining annulus 43 that is secured over the collar by machine screws 44. The specially shaped head 39 of the screw 40 thus is rotatably retained within the slide 33.

Fixed to the specially shaped head 39 is a fork 45 which projects into the counterbore 38 and there embraces a center piece 46 to which it is pivoted. Another fork 47 also embraces the center piece 46 to which it is pivoted on an axis perpendicular on that which the fork 45 is pivoted to the center piece. A third fork 48 is fixedly connected to a short rod 49 which in turn is non-rotatably keyed to the fork 47 and is universally pivotally connected through a second center piece 50, a fourth fork 51 and a second short rod 52 to a hand wheel 53 having a handle 54. The elements 45 to 52 inclusive constitute a flexible shaft which so connects the hand wheel 53 to the specially shaped head 39 of the screw 40 that the screw 40 can be turned in either direction by means of the hand wheel 53 to be screwed into or backed out of the solid portion 41 of the lever 22.

The screwing in or backing out can be done regardless of the angle at which the lever 22 extends from the fulcrum pin 23 and can be done while the lever is being moved up and down by the action of the crank shaft 6 through the auxiliary crank and the connecting link 30. Hand wheel 53 is held in a fixed position of frame 1 by bracket 55 in which it is journaled. Lever 22 is coupled to screw 40 by the universal coupling 46 pivoted on the axis of fulcrum pivot 23. As the screw 40 is screwed in or backed out of the solid portion 41 of the lever 22 the nose pivot 21 and the power pivot 31 are moved toward or away from the fulcrum bearings 32 of the lever 22, and the angles at which the connecting link 30 and the rack bar 20 meet the lever 22' are changed. The combined result of these changes in the lengths and proportions of the lever arms and the angles at which the connecting link and rack bar meet the lever is to micro-metrically adjust the stroke of the rack 19 and the consequent length of the increments of advance of strip stock through the power press. This micro-adjustment of the increments of advance takes place while the machine is running and while the operator can observe the gradual adjustment as it is effected by his manipulation of the hand wheel 53.

The form of device described herein and illustrated in the accompanying drawings is to be regarded as exemplary only and not as placing limitation on the spirit and scope of the invention.

I claim:

1. In a machine for processing strip stock, said machine having a frame, a crank, a ram coupled to said crank to reciprocate as said crank rotates, and a feeder for feeding successive increments of such sheet metal strip stock into positions to be acted upon by said ram, the combination therein of an auxiliary crank the throw of which is proportional to the lengths of the successive increments of such strip stock, a connecting link one end of which is rotated by said auxiliary crank, a lever the power pivot of which is pivoted to the other end of said connecting link, a fulcrum pivot for said lever fixed with respect to said frame, a reciprocable element coupled to said feeder and pivoted to a nose pivot of said lever, said nose pivot being spaced along said lever from said power pivot, the strokes of said element being in overlapping sequence with the strokes of said ram and being proportional to the lengths of the successive increments of such strip stock so fed into positions to be acted upon, and means for altering the length of said lever between said fulcrum pivot and said power and nose pivots and thus effecting micro-adjustments of the lengths of the arms of said lever extending between said fulcrum pivot and said power pivot and between said fulcrum pivot and said nose pivot and their ratio to each other while said machine is running and thereby also effecting micro-adjustments of the strokes of said element and consequent micro-adjustments of the lengths of such successive increments of advance of such strip stock while it is being processed, said means for altering the length of said lever comprising a slide fixedly mounting said fulcrum pivot and mounted for movement along said lever, said lever having a tapped bore, a screw mounted for rotation and carried by said slide and engaging its threads with the threads of said bore in said lever for moving said lever endwise of said slide, a flexible shaft connected to said screw and means for rotating said flexible shaft and said screw mounted upon said frame.

2. A feeder for feeding successive increments of strip stock comprising a crank the throw of which is proportional to the lengths of the successive increments of said strip stock, a connecting link one end of which is rotated by said crank, a lever the power pivot of which is pivoted to the other end of said connecting link, a stationary fulcrum pivot for said lever, a reciprocal element for actuating said feed of said strip stock pivoted to a nose pivot of said lever, said nose pivot being spaced along said lever from said power pivot, the stroke of said reciprocal element being proportionate to the lengths of successive increments of said strip stock, and means for altering the length of stroke of said reciprocal element comprising means for altering the length of said lever between said fulcrum pivot and said power and nose pivots, said means for altering the length for said lever comprising a first slide element integral with said lever, a second slide element cooperating with said first slide element by relative longitudinal movement with respect to said lever, said stationary fulcrum pivot being pivotally coupled to said second slide element, a screw mounted for rotation in said second slide element and having a threaded shaft maintained in alignment with the longitudinal axis of said 6 lever, said first slide element having a tapped bore in alignment with the longitudinal axis of said lever and cooperating with said screw, a flexible shaft coupled to said screw on the axis of said fulcrum pivot, a drive for rotating said flexible shaft and a stationary mounting means for said drive.

References Cited in the file of this patent UNITED STATES PATENTS 601,398 Long Mar. 29, 1898 1,947,015 Littell Feb. 13, 1934 2,164,806 Eickman July 4, 1939 2,488,6 0 Stackawicz Nov. 22, 1949 2,514,261 Schefiey July 4, 1950 ,8 6, 93 Budlong Oct. 21, 1958 

1. IN A MACHINE FOR PROCESSING STRIP STOCK, SAID MACHINE HAVING A FRAME, A CRANK, A RAM COUPLED TO SAID CRANK TO RECIPROCATE AS SAID CRANK ROTATES, AND A FEEDER FOR FEEDING SUCCESSIVE INCREMENTS OF SUCH SHEET METAL STRIP STOCK INTO POSITIONS TO BE ACTED UPON BY SAID RAM, THE COMBINATION THEREIN OF AN AUXILIARY CRANK THE THROW OF WHICH IS PROPORTIONAL TO THE LENGTHS OF THE SUCCESSIVE INCREMENTS OF SUCH STRIP STOCK, A CONNECTING LINK ONE END OF WHICH IS ROTATED BY SAID AUXILIARY CRANK, A LEVER THE POWER PIVOT OF WHICH IS PIVOTED TO THE OTHER END OF SAID CONNECTING LINK, A FULCRUM PIVOT FOR SAID LEVER FIXED WITH RESPECT TO SAID FRAME, A RECIPROCABLE ELEMENT COUPLED TO SAID FEEDER AND PIVOTED TO A NOSE PIVOT OF SAID LEVER, SAID NOSE PIVOT BEING SPACED ALONG SAID LEVER FROM SAID POWER PIVOT, THE STROKES OF SAID ELEMENT BEING IN OVERLAPPING SEQUENCE WITH THE STROKES OF SAID RAM AND BEING PROPORTIONAL TO THE LENGTHS OF THE SUCCESSIVE INCREMENTS OF SUCH STRIP STOCK SO FED INTO POSITIONS TO BE ACTED UPON, AND MEANS FOR ALTERING THE LENGTH OF SAID LEVER BETWEEN SAID FULCRUM PIVOT AND SAID POWER AND NOSE PIVOTS AND THUS EFFECTING MICRO-ADJUSTMENTS OF THE LENGTHS OF THE ARMS OF SAID LEVER EXTENDING BETWEEN SAID FULCRUM PIVOT AND SAID POWER PIVOT AND BETWEEN SAID FULCRUM PIVOT AND SAID NOSE PIVOT AND THEIR RATIO TO EACH OTHER WHILE SAID MACHINE IS RUNNING AND 